Production and scavenging of reactive oxygen species in plant cells under cadmium stress

Abstract

Cadmium (Cd) causes the excessive accumulation of reactive oxygen species (ROS) in plant cells, inhibits plant growth, and reduces crop productivity (e.g., grain yields). However, our understanding of Cd migration, ROS accumulation, and the underlying mechanisms in plant cells remains limited. In this review, we summarize findings from peer-reviewed articles and their references regarding the mechanisms of Cd transport and adsorption in plant cells, plant responses to Cd toxicity, and future research directions to address current knowledge gaps. Cd migration within plant cells typically progresses through the cell wall, plasma membrane, cytoplasm, vacuolar membrane, and vacuole. Excess ROS produced by plant cells are primarily scavenged through enzymatic and non-enzymatic reactions. Further, nitric oxide signaling and sulfur metabolism play crucial roles in mitigating Cd toxicity. Additionally, crop responses to Cd can vary across different field experiments due to environmental factors. Establishing long-term field experiments can help minimize environmental interference in the response of crops to Cd. An interdisciplinary research approach has been employed to elucidate the mechanisms of energy metabolism involved in ROS scavenging. Simultaneously, addressing the problem of unclear signal transduction requires the identification of new ROS and redox sensors, redox relays, and regulatory hubs. Therefore, future research could focus on targeting Cd transport regulatory genes and cellular signaling pathways in plant cells to mitigate Cd toxicity, enhance plant productivity, and protect ecosystems.